This invention relates to the field of surgery, and more particularly to a plastic clip and method of applying the clip to tissues, particularly in microsurgical anastomoses.
The term "anastomosis" covers a variety of procedures in which blood vessels or other tubular members, such as parts of the colon, are joined or reconnected. Vessels may be joined in a variety of relative orientations, including end-to-side, and end-to-end. Solid tubular structures such as peripheral nerves can also be joined together, as well as solid structures such as subcutaneous tissue and skin.
Anastomoses are traditionally performed by suturing the vessels together at the juncture between them. Alternatives to suturing have been developed, in order to prevent thrombosis which tends to occur at the points of penetration of the sutures. One such alternative, particularly for larger vessels, involves mechanical connectors such as collars. A second alternative is the use of surgical clips which are applied along the vessel juncture to perform a holding function similar to that of sutures, without penetrating the vessel walls. Two such clips, developed by the present inventors, are shown in U.S. Pat. Nos. 4,586,503 and 4,733,660. As described in the former patent, the clips are applied over apposed edges of the vessels, the edges first being everted (turned outward) to form flanges that are gripped between the jaws of the clips.
The clips disclosed in the above patents are preferably made of metal, and are crimped (plastically deformed) in place over the edges of the everted tissues. This invention is distinguished from the above-mentioned patents in that the clips now proposed are made of plastic, which has certain advantages noted below, and in that rather than being crimped, the clips are opened by temporarily spreading their jaws, then allowed to recover to their original shape around the apposed tissues.
Plastic materials have a "memory" which causes them to return to their original shape in time, following deformation. This characteristic is used to advantage in the present invention. Furthermore, the use of plastic can be advantageous in that there are bioabsorbable plastics which may be employed at internal sites where bioabsorption is preferred or necessary for proper healing.